Computer-implemented method for simulating behavior of a screw connection between metal components of engineering structures
A simulation of real behaviour of a screw connection of metal components uses a finite elements method to determine suitable elements for building construction joints and their arrangement, and to determine their parameters, wherein the method uses models for simulation of contact between plates as well as shear load of a screw connection and axial load of the screw connection.
1. A computer-implemented method of simulating predictable behavior of a screw connection of metal components in building structures, screw connection comprising at least a screw and first and second metal components, the method comprising the steps of:
a) simulating the first and second metal components of a building structure,
b) replacing the first and second metal components with at least first and second simulated plates of shell components modeled by a finite-element method, wherein the plates comprise a number of elements interconnected by the mesh nodes, wherein
the first plate comprises at least two first nodes, and
the second plate comprises a at least two second nodes,
c) connecting the first and second plates with a screw model, including connections comprising:
a first connection of the first plate comprising the step of transferring a first load from the first nodes to only a single first point, and
a second connection of the second plate comprising the step of transferring a second load from the second nodes to only a single second point, and
wherein the screw model is between the first point and the second point, the screw model comprising:
a model simulating shear load of the screw connection, and
a model simulating axial load of the screw connection,
wherein the models of simulating shear and axial load simulate transfer of force and deformation load from the first point to the second point, and wherein the model simulating shear load of the screw connection comprises a subsystem simulating interaction of the screw with each one of the first and second metal components and a subsystem of shear deformation of the screw, and wherein the model simulating shear load is nonlinear,
d) determining the predictive behavior of the screw connection based on the simulated transfer of force and deformation load, and
e) using the predictable behavior to determine suitable metal components and screw connections in building structures.
2. The method of claim 1 , wherein the model for simulation of shear load comprises a mathematical model of plastic behavior of a screw under shear load.
3. The method of claim 1 , wherein the model for simulation of axial load comprises a mathematical model of one or more physical effects including a screw deformation constant, a plate deformation constant and a preload of the screw connection.
4. The method of claim 1 , wherein transfer of load from the nodes to the points comprises a continuous load on a screw head or a screw pad area that corresponds to a size of the screw head or a screw pad that is calculated by which a force constraint between the nodes and the points is obtained.
5. A computer-implemented method of simulating predictable behavior of a screw connection of beam elements in a building structure, screw connection comprising at least a screw and first and second beam elements the method comprising the steps of:
a) simulating a joint comprising a first beam element segment and a second beam element segment interconnected by a screw connection,
b) replacing the first and second beam element segments of the joint with at least first and second simulated plates of two-dimensional shell elements using a finite-element method, wherein the plates comprise a number of elements interconnected by mesh nodes of finite elements, wherein
the first plate comprises at least two first nodes, and
the second plate comprises at least two second nodes,
c) connecting the first and second plates with a screw model, including connections comprising:
a first connection of the first plate comprising the step of transferring a simulated first load from the first nodes to only a single first point, and
a second connection of the second plate comprising the step of transferring a simulated second load from the second nodes to only a single second point, and
wherein the screw model is between the first point and the second point, the screw model comprising:
a model simulating shear load of the screw connection, and
a model simulating axial load of the screw connection,
wherein the models of simulating shear and axial load simulate transfer of force and deformation load from the first point to the second point, and wherein the model simulating shear load of the screw connection is nonlinear,
d) determining the predictive behavior of the screw connection based on the simulated transfer of force and deformation load, and
e) using the predictable behavior to determine suitable beam elements and screw connections in building structures.
6. The method of claim 5 , wherein the beam elements are metal components of metal building construction.
7. The method of claim 5 , wherein the plates have a shape corresponding to shapes of the first and second beam element segments.
8. The method of claim 5 , wherein the simulated transfer of force from the first point to the second point is at a center of the screw connection.
9. The method of claim 8 , wherein an equilibrium model of forces and moments is created based on an overall load on the joint.
10. The method of claim 5 , wherein first and second plates have mesh nodes on the edges of plates which corresponds to end cross section of the beam element segments, wherein a load is applied to the mesh nodes on the edges of plates using a force multipoint constraint.
11. The method of claim 5 , wherein the model simulating shear load of the screw connections is divided into subsystems, comprising subsystems simulating interaction of the screw with each of the first and second beam elements and a subsystem of shear deformation of the screw in the screw connection.
12. The method of claim 11 , wherein the subsystems are determined based on proportions and material properties of the first and second beam elements and the screw.
13. The method of claim 5 , wherein the model for simulation of shear load comprises a mathematical model of plastic behavior of a screw under shear load.
14. The method of claim 5 , wherein the model for simulation of axial load comprises a mathematical model of one or more physical effects including a screw deformation constant and a preload of the screw connection.
15. The method of claim 5 , wherein transfer of load from the nodes to the first and second points comprises a continuous load on a screw head or a screw pad area that corresponds to a size of the screw head or a screw pad that is calculated by which a force constraint between the nodes and points is obtained.